Lake St. Clair: toxic algae advisories
Lake St. Clair, Missouri.
What the state's records say
Reports on file, with no advisory level the state has classified.
That reflects what the state knew on that date. It is not a finding that the water is safe now: blooms can return within days, and many are never reported.
Before you go, check the state's official algae page and any signs posted at the water.
Dogs at Lake St. Clair
The state has reports on file for Lake St. Clair but has not classified an advisory level, so the records cannot answer this. Keep your dog out of discolored or scummy water.
Reported spots
The state records each report at a spot, such as a beach or a boat ramp. Each spot's latest deciding record:
| Spot | Status |
|---|---|
| Lake St. Clair | Reports on file, with no advisory level the state has classified. |
Advisory history
Every case the state has published for Lake St. Clair, newest first. Each case carries its current status code; the label beside it is this site's reading of the code.
| Date | Spot | State's level | Notes |
|---|---|---|---|
| Jul 11, 2025 | Lake St. Clair | Below threshold (notthr) | Case closed. |
Source
Missouri data: Missouri Department of Natural Resources, Harmful Algal Bloom response map. Status codes are the department's; their plain-English labels here are this site's reading of the codes. The state's data. An advisory ends only when the department records a dissipation date. A closed case without one is not read as an end.
Required by the State of Missouri:
The data made available here has been modified for use from its original source, which is the State of Missouri. THE STATE OF MISSOURI MAKES NO REPRESENTATIONS OR WARRANTY AS TO THE COMPLETENESS, ACCURACY, TIMELINESS, OR CONTENT OF ANY DATA MADE AVAILABLE THROUGH THIS SITE. THE STATE OF MISSOURI EXPRESSLY DISCLAIMS ALL WARRANTIES, WHETHER EXPRESS OR IMPLIED, INCLUDING ANY IMPLIED WARRANTIES OF MERCHANTABILITY, OR FITNESS FOR A PARTICULAR PURPOSE. The data is subject to change as modifications and updates are complete. It is understood that the information contained in the Web feed is being used at one’s own risk.